Variable pitch propeller mechanism



May 31, 1932. J. R. ZIPAY VARIABLE PITCH PROPELLER MECHANISM Filed April 21, 1931 Patented May 31 1932 UNITED STATES JOHN RAP? ZIPAY, OF PITTSBURGH, PENNSYLVANIA VARIABLE .PI'ICH PROPELLER MECHLLNISM' Application filed April 21,

In the case of variable pitch propellers for aeroplanes and like purposes the stems of' the propeller blades are usually journaled in the bores of the propeller bushing which is mounted on and disposed transversely to the propeller shaft.

More particularly my present invention relates to that type of variable pitch propeller mechanism wherein balancing weights are provided for the propeller blades and ar-' ranged radially of the axes of the latter to counteract the forces put into effect by the revolution of the propeller and by their in-' ertia to effect variation of blade-pitch.

In propeller mechanism of this general type, such for instance as is disclosed in Letters Patent of the United States 1,852,500,

issued to me on April 5, 1932, variations in pitch are effected and regulated and the pitch is maintained by means of lever mechanism under the control of the operator and operating by contact with a member or collar slidable on the propeller shaft and rotating there-. with, said member being connected by links and cranks to the stems of the propeller blades.

Such contact is either directly between the lever and the rotating member or between the lever and a disk loose on the member, and in either case considerable friction and wear are involved, the resistance qf the blades being exterted upon the lever.

One of the objects which I have in view is the provision of means whereby the propeller blades in the normal flight of the aeroplane will automatically maintain the pitch to which they have been set.

Thus after the aeroplane has attained its normal flight-level and the operator by means of his lever has adjusted the pitch, the lever may be retracted and such pitch w1ll be auto matically maintained during normal flight. I also provide means whereby the mechas' nism may be adjusted so that any desired pitch may be obtained during normal flight. Novel features of construction and also of arrangement of parts will appear from the following description.

In the accompanying drawings, wherein I have illustrated a practical embodiment of 1931. Serial No. 531,711.

the principles of my invention, Fig. 1 is a view in plan showing a portion of anaeroplane including the front of the fusilage, the propeller shaft, the propeller bushing, the propeller blades and the pitch regulating and 66 control mechanism.

Fig. 2 is an enlar ed detail in plan of the bushing and the baIancing weights, &c.

Fig. 3 is a sectional view taken along the line 33 in Fig. 2.

Fig. 4 is a detail showing the rear elevation of the propeller shaft sleeve and the forked operating lever.

Fig. 5 is a detail of one of the balancing weights and its arm. 7 Referring to the drawings 1 represents the front portion of the fuselage of an aeroplane, and 2 the propeller shaft driven in the usual manner by the motor 2a. The shaft 2 extends forwardly from the fuselage and has keyed or otherwise fixed on its outer end the partible bushing 3' which is disposed transversely of the shaft 2. The bushing parts are clamped together as by the straps 4 and in the end bores of the bushing at either side of the shaft 2 the stems 5 of the propeller blades 6 are journaled and held against longitudinal movement relative to the bushing.

The method of such journaling and retention is not shown in detail but it may be such as is disclosed in my above mentioned Letters Patent.

Adjacent to the ends of the bushing the I splitcollars 7 are clamped on the stems 5, said collars having their free ends provided with tangentially disposed sleeves 8through which the clamping bolts 9 extend, the nuts 10-being tightened on the ends of said bolts. The stems 5 are provided with arcuate flattened portions 11 extending circumferentially of the stems and which are engaged by the sleeves 8 to hold the collars against accidental rot-ative movement on the stems after the clamping bolts have been tightened. By elongating such arcuate surfaces circumferentia-lly of the stems the collars may be loosened and the propeller blades turned 'relative to the bushing to adjust their pitch, l:

The collars 7 are provided with a series of teeth which form segmental gears 12 and which are disposed at the front of the bushing 3, as indicated in Figs. 2 and 3.

13 and 14 represent a pair of horizontally end of the shaft 2 which bearings may be cast integral with the front bushing part or may be secured thereto. The two bearings of a air are spaced apart so that the clamping ands 4 may be applied to clamp the parts of the bushing 3 together.

In each of said'pairs of bearings is ]Ol1I- naled a shaft 15 on the outer end of which is mounted a segmental pinion 16 in mesh with the se mental gears 12. The inner ends of said sha ts are provided with radially disposed crank arms 17 which are set at substantially 180 degrees from each other and to the outer ends of which are pivotally attached the front ends of the links 18, one of said links being above and the other below the bushing. The rear ends of said links are ivotally connected to the yoke-members 19 xed on the front face of the head 20 of the collar 21 which is slidably mounted on a sleeve 22 which in turn is fixed on and surrounds the shaft 2 between the bushing and the front of the fuselage. The collar 21 is splined on the sleeve 22 so as to slide longitudinally of the latter but to rotate with the sleeve and shaft.

23 represents a helical spring surrounding the sleeve 22, having its front end bearing on the rear end of the tubular boss 24 which is formed .on the rear of the bushing and through which the shaft 2 extends, and having its rear end bearing on the head 20. The

spring thus tends to cause the bushing to retreat rearwardly along the shaft.

Rotatably mounted on the rear portion of the collar 21 is the disk 25.

Near its rear end the sleeve 22 is provided with athreaded portion upon which is screwed the limiting nut 26 and a lock nut 27 which serve to determine the limit of rearward travel of the collar 21 and which may be adjusted along the sleeve 22 to vary such limit.

28 represents a lever pivotally mounted intermediate of its ends on a bracket 29 carried by the fuselage 1. The forked end of the lever straddles the shaft 2 and the sleeve 22 and is arranged to bear forwardly against the disk and thus be employed to move the collar 21 forwardly along the shaft or to limit the rearward movement of said collar.

The other end of the lever 28 is connected to a suitable manual control device general- 1y indicated at 30 and mounted on the fusel e in convenient reach of the'operator.

lamped about the stems 5 next to the segjustable about the stems in like manner as tachably mounted the split wei hts formed of the parts 33 which are groove on their abutfaces to receive the arm 32, bolts 34 extin ten ing through registering holes in the alined bearings at either side of the front weight parts and the lever to clamp the 7 mental gear 12 are the split collars 31, ad-

. weights to the levers.

The weights act to balance the expansive force of the spring 23 when the aeroplane is in normal flight, the pitch of the propellers having been set at the desired angle by means of the control lever. To obtain this balance the weights are adjusted about the propeller stems to the proper position.

In taking off or landing the propellers are set at their minimum pitch, the forked end of the lever 28 being retracted and the spring 23 causing the collar 21 to retreat rearwardly until halted by the limiting nut 26. The retreat of the collar, through the links 18, the cranks 17, the pinions l6 and the gears 12 rotates the propeller blades. By adjusting the stems of the propellers relative to the levers 17 and by adjusting the limiting nut along the sleeve 32 the minimum propeller pitch may be regulated to suit requirements, such as type of aeroplane, &c.

lVhen the pitch of the propellers is to be increased, as when the aeroplane has risen and is to travel in normal flight, the operator by means of the control device 30, swings the lever 28 so as to force the collar forwardly toward the bushing to the desired degree, the links 18 and the cranks 17 rotating the shafts, the pinions l6 and the gears 12, thus rotating the propeller blades and increasing their pitch. When the blades have thus been ad- ]usted at the desired pitch the lever 28 is retreated out of contact with the disk 25 so that no wear or friction occurs while the retreat of the collar is prevented by balancing effect of the weight.

Under normal flight conditions the inertia of the weights 33, working against the expansion forces of the spring 23 will balance the force of the spring 23, thus automatically maintaining the propellers at their adjusted pitch. When the aeroplane is to land, the motor is slowed down, thus reducing the speed of revolution of the propeller and consequently reducing the inertia forces of the 'Weights, and therefore the spring 23 will be enabled to cause the collar 21 to retreat, reducing the propeller pitch.

The meshed engagement between the pinions 16 and the gears 12 serve as looking or retarding means to retain the adjusted pitch I of the propellers in normal flight.

The shafts 15 and the pinions 16 are mounted out of the way in front of the propeller bushing, thus enabling the propeller bushing and blades to be located nearer the front of the fuselage. Thus the length of the propeller'sh'aft is reduced-and the torque lessened.- the stems of the propeller blades, and crank adjusted without The pitch of the propeller blades ma be the bu ing by loose he nuts 10 an turning the propellers on their longitudinal axes relative to the bushingl an the split collars 7. When the pitch of t e blades is thus adjusted, it is necessary to adjustthe leverage of the weights 33 so that they may balance the expansive force of the. s ring 23 and thus permil: the propeller bla esto" automaticall re- 'tain the pitch to which they are set in 'ght bymeansof the lever 28. e

"The weights are adjusted by loosening the split collars 31 and turning themon the stems 'iiecessary degree and then reclamping the's'plitcollarsto t e stems Y expansive force of the spring 23 is selected to ehable it to perform the functions above referred to and'will va under difierent conditions. Likewise the everage of the weights 33 may. be regulated by providing 'a'nns32 of the proper length;

I cla1m:.- g 1. In a -variablepiteh lfiropeller mechanism for-aeroplanes and e purposes, the combination with the propeller shaft, a pro peller bushing fixed on said shaft and distransversely thereofppropeller blades g their stems journaled 1n the bores of-sa'id bushing-, and a member mounted to slide lo 'tudinally of said propeller shaft but rotating therewith, of operative connection between said member and said propeller blades whereb the movement of the member relative to sai shaft causes said blades to ro-' tateon their .a'xes' relative to the bushing,

said connection consisting of shafts journaled on said 'bushin and revol therewith about the axis 0 the propeller s aft, geared connection between said last-mentioned shafts and tbe"stems ofjthe propeller blues and crank and link 'coi'mection between said last mentioned shaftsand said member whereby the movement of said memberrelative to the pro llerl shaft causes said last imentioned sha s to rock and thus rotate the blades on their axes.

1. 2:11: a variable pitchpropeller mechanism for aeroplanes and hke purposes thecombination with the propeller shaft,a propeller bushing fixed on said shaft and dis-'- Eosedtransversely thereofgtpropeller blades aving their stems journal in the bores of ,said bushin' and a' member mountedto slide dim y of said propeller shaft but T titing therewith, of operative connection. be:

tween-said member and said'p'ropeller blades whereby-- the movement of the member relative to saidshaft causes; said blades to rotate fonheir axes relative t said consisting of shafts ,ji m aled on said busbini'I-and revolving therewith about the of t epropeller shafh-geared connec-r tionbetween said lasticmentioned shafts and said bushing propeller and connection between said last mentioned shafts. and said member whereby the movement of said member relative to the propeller shaft causes said last mentioned shafts to rock and thus rotate the propeller blades A transversely thereof, propeller blades havin their stems journaled in the bores of sai bushing, and a member mounted to slide longitudinally of said propeller shaft but rotatmgtherewith, of operative connection between saidimember and said propeller blades whereby the movement of the member rela tive to saidshaft causes said blades to rotate on their axes relative to the bushing, said connection consisting of shafts journaled on and revolvin therewith about the axis of the pro ller s aft, geared connection between said last mentioned-shafts and the stems of the propeller blades, and crank and link connection between said last mentioned shafts and said member whereby the movement of said member relative tothe pro llershaft causes said last mentioned sha s to rockand thus rotate the propeller blades on their axes; spring-means arranged to move said member whereby to reduce the pitch of the propeller blades, and means under the control of the. o rator arranged to engage said member an move'it in opposition to said spring-means whereby to'increase the pitch of the propeller blades.

\ 4; In a variable pitch propeller mechanism for aeroplanes and likepurposes, the combination with the propeller shaft, a propeller bushing fixed on saidshaft and disposedtransversely thereof, ropeller blades havi their stems journale in the bores of sai bushing, and a member mounted to slide longitudinally; of said propeller shaft but rotating therewith, of operative connection bethe combi-.

ill

link "connection between said last mentioned shafts and said member whereb the movement of said member relativeto t e propeller.

shaft causes said last mentioned shafts to bushing, and a member mounted to slide lonm gitudina-lly ofxsaid propeller shaft but rotating therewith, of operative connection between said member and said propeller blades whereby the movement of the member relative to said shaft causes said blades to rotate on their axes relative to the bushing, said connection consisting of shaft journaled on said bushing and revolving therewith about the axis of the propeller shaft, geared connection between said lastmentioned shafts and the stems of the propeller blades, and crank and link connection betwen said last mentioned shafts and said member whereby the movement of said member relative to the propeller shaft causes said last mentioned shafts to rock and thus rotate the propeller blades on their axes, spring-means arranged to move said member whereby to reduce the pitch of the propeller blades, means for regulatin the spring-actuated movement of the memfier whereby the minimum pitch of the propeller blades may be adjusted, and means under the control of the operator arranged to engagesaid member and move it in opposition to the spring-means whereby to increase the pitch of the propeller blades.

6. In a variable pitch propeller mechanism for aeroplanes and like purposes, the combination with the propeller shaft, a propeller bushing fixed on said shaft and disposed transversely thereof, propeller blades having their stems journaled in the bores of said bushing, and a member mounted to slide longitudinally .of said propeller shaft but rotating therewith, of operative connection between said member and said propeller blades whereby the movement of the member relaive to said shaft causes said blades to rotate on their axes relative to the bushing, said connection consisting of shafts journaled on said bushing and revolving therewith about the axis of the propeller shaft, geared connection between said last mentioned shafts and the stems of the propeller blades and crank and link connection between said-last mentioned shafts and said member whereby the movement of said 111ember relative to the pro ller shaft causes said last mentioned sha to rock and thus rotate the propeller .0 blades on their axes, spring-means arranged to move said member whereby to reduce the pitch'of the propeller blades, means for regu-' lating the spring-actuated movement of the member whereby the minimum pitch of the propeller blades may be adjusted, and balancing weights mounted radially 'of" the" stems of the propeller blades and'moving therewith and arranged to oppose the action of the spring-means.

7. In a variable pitch propeller mechanism for aeroplanes and like purposes, the combination with the propeller shaft, a. propeller bushing fixed on said shaft and dis posed transversely thereof, propeller blades having their stems journaled in the bores of said bushin and a member mounted to slide longitudina ly of said propeller shaft but rotatingtherewith, of operative connection between said member, and said propeller blades whereby the movement of the member relative to said shaft causes said blades to rotate on their axes relative to the bushing, said connection consisting of shafts journaled on said bushing and revolving therewith about the axis of the propeller shaft, geared connection between said last mentioned shafts and the stems of the propeller blades, and crank and link connection between said last mentioned shafts and said member whereby the movement of said member relative to the propeller shaft causes said last mentioned shafts to rock and thus rotate the propeller blades on their axes, spring-means arranged to move said member whereby to reduce the pitch of the propeller blades, means for regulating the spring actuated movement of the member whereby the minimum pitch of the propeller blades may be adjusted, balancing weights mounted radially of the stems of the propeller blades'and moving therewith and arranged to oppose the action of the springmeans, and means under the control of the operator arranged to engage said member I and move it in opposition to the spring-means whereby to increase the pitch of the propeller blades.

8. In a variable pitch propeller mechanism for aeroplanes and like purposes, the

combination with the propeller shaft, a pro-" peller bushing fixed on said shaft and dis-- posed transversely thereof, propeller blades having their stems journaled in the bores of said bushing, and a member mounted to slide longitudinally of the propeller shaft but rotating therewith, of a pair of shafts journaled on said bushing and revolving therewith, crank linkage between said member and said last mentioned shafts whereby the movement of said member causes said shafts to rock, pinions on said shafts, and gears on the stems of the propeller blades meshing with said pinion.

9. In a variable pitch propeller mechanism for aeroplanes and like purposes the combination N with the propeller shaft, a

ed to slide longitudinally of the propeller propeller bushing fixed on said shaft andshaft but rotating therewith, of a pair of shafts journaled on said bushin and revolving therewith, crank linkage etween said member and said last mentioned shafts whereby. the movement of said member causes said shafts to rock,'pinions on said shafts, and gears'on the stems of the propeller bladesmeshing with said pinion, said blades being adjustable about their axes relative to said gears.

10. In a variable pitch propeller 'mechanism for aeroplanes and like purposes, the combination with the propeller shaft, a propeller bushing fixed on said shaft and disposed transversely thereof, propeller blades having their stems journaled in saidbush-' ing, amember slidably mounted longitudinally of the shaft, lever connection between the propeller blades and said member whereby the movement of the member causes the stems of the propeller blades to turnin the bushing thereby varying the pitch of said blades, spring-means actuating said member to decrease said pitch, means for limiting the pitch-decreasing movement of the member, means under the control of the operator for moving the member to-increase the pitch,

- r and means for adjusting the propeller blades relative to said lever connection whereby to set the blades to a desired minimum pitch.

11'. In a variable pitch propeller mechanism for aeroplanes andlike purposes, the

combination with the propeller shaft, a

propeller bushing fixed on said shaft and disposed transversely thereof, propeller blades having their stems journaled insaid bushing, a member slidably mounted longitudinally of the shaft, lever connection between the propeller blades and said member whereby the movement of the member causes the stems of the ropeller blades to turn in the bushing there y varying the pitch of said weights about said stems whereby to maintain the propeller blades at a'selected pitch blades, spring-means actuating said member to decrease said pitch, means for limiting the pitch-decreasing movement of the member, means under thecontrol of the operator for moving the member to increase the pitch, balancing weights mounted radially of the axis of the propeller blade stems and moving therewith, and means for adjusting said during the normal flight of the aeroplane.

12; In variable pitch propeller mechanism for aeroplanes and the like, the combination with'the propeller shaft, a bushing mounted on said propeller shaft and provided with bores disposed radially of said shaft and propeller blades having their stems journaled in v said bores so as to be turned to vary the pitch of the propeller blades, of bearings on said bushing, shafts journaled in said bearings and disposed parallel with the axes of the propeller blades, gears mounted on said stems, pinions mounted on said second named shafts and in mesh with said gears, cranks on said second named shafts, a member slidably mounted on the propeller shaft, links connecting said member w1th said cranks, resilient means for moving said member relative to said shaft to reduce the pitch of the propeller blades, and balancing weights car ried by the stems of said propeller blades and disposed radially thereof.

13. In variable pitch propeller mechanism for aeroplanes and the like, the combination with the propeller shaft, a bushing mounted on said propeller shaft and provided with bores disposed radially of said shaft and propeller blades having their stems journ'aled in, said bores so as to be turned to vary the pitch of the pro eller blades, of bearings on said bushing, s afts journaled in said. bearings and disposed parallel with the axes of the propeller blades, gears mounted on said posed radially thereof, and means under the control of the operator for adjusting the minimum pitch of the propeller blades.

14. In variable pitch propeller mechanism for aeroplanes and the like, the combination with the propeller shaft, a bushing mounted I on said propeller shaft and provided with bores disposed radially of said shaft and pro 'peller blades having their stems journaled in said bores so as to be turned to vary the pitch of the propeller blades, of bearings on said bushing, shafts journaled in said bearin s and disposed parallel with the axes of t e propeller blades, gears mounted on said stems, pinions mounted on said second named shafts and in mesh with said gears, cranks on said second named shafts, a memberslidably mounted on the propeller shaft, links connecting said member with said cranks, resilient means for moving said member relative to saidshaft to reduce the pitch of. the propeller blades, balancing weights carried by the stemsaof said propeller blades and dis pos'ed radially thereof, and means under the control of the operator for moving said memher to increase blades.

Signed at Pittsburgh, Pa., this 18th day of April, 1931.

JOHN RAPP ZIPAY.

the-pitch of the propeller 

